OBJECTIVES: 1) To develop more adequate mathematical descriptions for ionic currents and nerve membranes under voltage clamp control. This is being done by studying the effects of physical and chemical agents on nerve membrane ionic conductances in the voltage clamp; 2) To understand the mechanisms underlying excitation and impulse propagation. Our approach here is to study the effects of geometrical properties on propagation. BIBLIOGRAPHIC REFERENCES: Moore, J.W., F. Ramon & R. Joyner. (1975). Axon voltage-clamp simulations. I. Methods and tests. Biophys. J. 15, 11-24. Moore, J.W. and E.B. Cox (1976). A kinetic model for the sodium conductance system in sqid axon. Biophys. J. 16, 171-192.